The first ever game I remember playing was Sonic the Hedgehog on my dad's Mega-Drive, I loved it to bits, and Sonic 2. I watched the Sonic cartoons when I was younger as well, which I always thought was brilliant, and I had a Sonic 2 T-shirt that I went to school with (my first Primary School had no uniform).
I never got a Saturn, but my dad got me the PC version of Sonic CD, which I thought was brilliant besides the fact I had no idea what was going on at the time of playing, only that a girl hedgehog had been kidnapped by Metal Sonic and I had to rescue her.
Then I remember going to Toys R Us and playing the Dreamcast for the first time, I thought the whale Jumping out of the water and wrecking the runway was awesome, the graphics were outstanding at the time.
I got a GC because Sonic Adventure 2 Battle was on it, and Sonic Advance was my second GBA game. Lately I haven't been into Sonic games as much though, the last one I fully completed was Heroes, but I've ordered Sonic Colours off Amazon and I'm sure that Sonic Generations will be excellent.
TLDR: Sonic shaped my young gaming life.